Audio conference apparatus

ABSTRACT

In an audio signal transmission/reception device that receives and emits sounds so as to perform transmission and reception of audio signals via communications, user operability can be improved and the size of a main unit can be reduced. It is equipped with a speaker array for arranging a plurality of speaker units, which are arranged on the lower surface of the main unit, and a microphone array for arranging a plurality of microphones, which are arranged on the side surface of the main unit in its longitudinal direction. Legs having hollow structures are attached to the main unit so as to support the main unit at a prescribed height above the mount surface (e.g., the surface of a desk) and to secure good sound emission characteristics of the speaker array.

TECHNICAL FIELD

The present invention relates to audio signal transmission/receptiondevices, generally known as audio conference devices, equipped withspeakers, microphones, and operation controls, which are applied toaudio signal transmission/reception systems enabling transmission andreception of audio signals between multiple audio signaltransmission/reception devices.

The present application claims priority on Japanese Patent ApplicationNo. 2005-312964 filed in Japan on Oct. 27, 2005, the content of which isincorporated herein by reference.

BACKGROUND ART

Conventionally, audio signal transmission/reception devices equippedwith microphones, speakers, and operation controls have been known,wherein Voicepoint IP shown in Non-Patent Document 1 provided by NipponElectronic Co. Ltd. (NEC) has been known, for example. FIG. 7 is aperspective view of a conventionally known audio signaltransmission/reception device 100. The audio signaltransmission/reception device 100 includes a main unit (housing) 101having a prescribed shape, a speaker 102 mounted on the center of thesurface of the main unit 101, a plurality of microphones 103 arranged inthe periphery of the speaker 102, and an operation control (console) 104arranged in the front side of the surface of the main unit 101.

-   Non-Patent Document 1: Voicepoint IP, NEC (which can be retrieved    via the Internet;-   URL: http://www.nec-eng.com/pro/vp_ip)

The aforementioned audio signal transmission/reception device 100 isapplied to an audio signal transmission/reception system includingmultiple audio signal transmission/reception devices, wherein audiosignals converted by the microphones 103 of the audio signaltransmission/reception device 100 are transmitted to a counterpart audiosignal transmission/reception device and wherein the speaker 102produces sound based on received audio signals, which are transmittedfrom the counterpart audio signal transmission/reception device and arereceived. By arranging the speaker 102 on the surface of the main unit101, it is possible to arrange the main unit 101 on a desk, thus placinga user's head above the main unit 101.

It allows the user to operate the operation control 104 so as to performsound reception setups of the microphones 103 and sound emission setups(volumes etc.) of the speaker 102, wherein sound reception setups andsound emission setups can be appropriately changed. The audio signaltransmission/reception device 100 is normally arranged on a desk; hence,the operation control 104 is arranged in the front side of the surface.

DISCLOSURE OF INVENTION Problem to be Solved by the Invention

The conventionally-known audio signal transmission/reception device 100is designed such that the speaker 102, the microphones 103, and theoperation control 104 are all arranged on the surface of the main unit101 in consideration of the user operability and sound emissioncharacteristics. For this reason, it is difficult to reduce the size ofthe main unit 101.

In order to realize hands-free audio signal transmission/receptiondevices (e.g., telephone devices), it is a recent trend to use speakerarrays having sound emission characteristics of narrow directivities andmicrophone arrays having sound reception characteristics of narrowdirectivities. Speaker arrays are each designed to align multiplespeakers in order to realize adequate sound emission directivitycontrols, while microphone arrays are each designed to align multiplemicrophones in order to realize adequate sound reception directivitycontrols. For this reason, when a speaker array or a microphone array isapplied to the conventionally-known audio signal transmission/receptiondevice 100, it is a problem that the main unit 101 is increased in size.

It is an object of the present invention to improve user operability andsound reception/emission characteristics and to provide an audio signaltransmission/reception device whose size can be reduced even when aspeaker array and a microphone array is applied thereto.

Means for Solving the Problem

An audio signal transmission/reception device of the present inventionis constituted by a main unit and a plurality of speaker units and isalso equipped with legs, which support a speaker array arranged on thelower surface of the main unit such that the sound emission side thereofis positioned at a prescribed height above the mount surface for themain unit.

Since the speaker array is arranged on the lower surface of the mainunit, it is possible to arrange the operation control and the speakerarray relative to the main unit in a three-dimensional manner; hence, itis possible to reduce the size compared with the conventionally-knownaudio signal transmission/reception device arranging the operationcontrol and speaker on the upper surface of the main unit. In addition,the main unit is supported by legs at a prescribed height above themount surface for the main unit, sound beams are emitted downwardly fromthe speaker array and are reflected by the surface (e.g., the surface ofa desk) so as to slantingly propagate upwards. Thus, it is possible tosecure sound emission characteristics similar to those of the foregoingconstitution arranging the speaker array on the surface of the mainunit.

In addition, it is possible to secure good user operability by arrangingthe operation control on the surface of the main unit.

Furthermore, it is possible to arrange a microphone array for aligningmultiple microphones in the side surface of the main unit. Thus, it ispossible to efficiently receive sound at the side portion of the mainunit and to reduce the size of the main unit in comparison with theforegoing constitution arranging microphones on the surface of the mainunit.

The main unit of the aforementioned audio signal transmission/receptiondevice substantially has an elongated rectangular parallelepiped shape,wherein the microphone array is arranged on the side surface of the mainunit in its longitudinal direction, and at least one connector forestablishing a connection with an external device is arranged on theside surface of the main unit in its width direction. Thus, it ispossible to reduce the size of the main unit in comparison with theforegoing constitution arranging connectors on the surface of the mainunit.

By making the aforementioned legs have hollow structures, it is possibleto effectively prevent the directivity of a sound beam emitted from thespeaker array from being changed by the legs. Thus, it is possible toeffectively prevent sound emission characteristics of the speaker arrayand reflection characteristics on the surface from being changed by thelegs.

Effect of the Invention

The audio signal transmission/reception device of the present inventionis designed such that the speaker array is arranged on the lower surfaceof the main unit, the microphone array is arranged on the side surfaceof the main unit, and the operation control is arranged on the surfaceof the main unit; hence, it is possible to reduce the size of the mainunit, and it is possible to secure good sound emission characteristicsand sound reception characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

[FIG. 1] A perspective view showing the exterior appearance of an audiosignal transmission/reception device in accordance with a preferredembodiment of the present invention.

[FIG. 2] Views for observing the audio signal transmission/receptiondevice in X-Y axes directions, wherein (A) is a plan view of the audiosignal transmission/reception device, (B) is a rear view of the audiosignal transmission/reception device in a -Y-axis section, and (C) is afront view of the audio signal transmission/reception device in a Y-axissection.

[FIG. 3] (A) is a right side view of the audio signaltransmission/reception device in an X-axis section, and (B) is a leftside view of the audio signal transmission/reception device in a -X-axissection.

[FIG. 4] A bottom view showing the audio signal transmission/receptiondevice excluding a lower grill, in which a speaker array includingmultiple speakers is arranged.

[FIG. 5] An enlarged perspective view showing the audio signaltransmission/reception device excluding the lower grill, whichcorresponds to the bottom view shown in FIG. 4.

[FIG. 6] A cross-sectional view of the audio signaltransmission/reception device shown in FIG. 4 taken along line A-A.

[FIG. 7] A perspective view showing the exterior appearance of aconventionally-known audio signal transmission/reception device.

DESCRIPTION OF REFERENCE NUMERALS

-   1 audio signal transmission/reception device-   2 main unit-   3 leg-   4 operation control-   5 LED display-   6 connectors-   23 speaker device-   24 microphone array-   25 frame-   26 support board-   41 LCD-   42 operation keys-   43 operation keys-   44 operation keys-   51 LED-   61 modular jack-   62A audio input terminal-   62B audio output terminal-   63 power terminal-   231 speaker array-   241 microphone-   SP speaker unit

BEST MODE FOR CARRYING OUT THE INVENTION

The preferred embodiment of the present invention will be described indetail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing the exterior appearance of an audiosignal transmission/reception device 1, which is generally known as anaudio conference device, according to the embodiment of the presentinvention. The audio signal transmission/reception device 1 is connectedto the Internet and LAN (Local Area Network) so as to performtransmission and reception of audio signals with a counterpart audiosignal transmission/reception device (not shown) located at a remoteplace, thus realizing audio conference therebetween.

In FIG. 1, the front side of the audio signal transmission/receptiondevice 1 is denoted as a Y-axis section, the rear side is denoted as a-Y-axis section, the right side is denoted as an X-axis section, and theleft side is denoted as a -X-axis section. FIG. 2(A) is a plan view ofthe audio signal transmission/reception device 1; FIG. 2(B) is a rearview of the audio signal transmission/reception device 1 in the -Y-axissection; and FIG. 2(C) is a front view of the audio signaltransmission/reception device 1 in the Y-axis section. FIG. 3(A) is aright side view of the audio signal transmission/reception device 1 inthe X-axis section, and FIG. 3(B) is a left side view of the audiosignal transmission/reception device in the -X-axis section.

The audio signal transmission/reception device 1 is formed using a mainunit 2 having an elongated rectangular parallelepiped shape, which issupported at a prescribed height above the surface (e.g., the surface ofa desk) by means of legs 3 having U-shapes that are engaged externallywith both sides thereof. The main unit 2 is constituted by an upperpanel 20, a lower grill 21, and a pair of side panels 22 (i.e., 22A,22B) and is also equipped with an elongated speaker device 23 (see FIG.5) having a speaker array 231 (see FIG. 4) therein and two series ofmicrophone arrays 24 (see FIG. 5).

The speaker array 231 is linearly aligned in the lower portion of thespeaker device 23 in its longitudinal direction, and the microphonearrays 24 are linearly aligned on both sides of the speaker device 23 inits longitudinal direction. Detailed constitutions of the speaker device23, the speaker array 231, and the microphone arrays 24 will bedescribed later.

The upper panel and the side panels 22 are composed of a resin, andcover the internal structure including the speaker array 231 and themicrophone arrays 24. The upper panel 20 has an elongated U-shape incross section, while the side panels 22 have substantially planarshapes. The lower grill 21 has a U-shape in cross section so as not todisturb sound emission of the speaker array 231 and sound reception ofthe microphone arrays 24, wherein it is formed using a punch-mesh steelplate.

The operation control 4 is formed in the X-axis section of the upperpanel 20, and the LED display 5 is formed in the center portion. Asshown in FIG. 2(A), the operation control 4 includes an LCD (LiquidCrystal Display) 41 for displaying setups and operation keys 42 such asa ten-key unit. The operation keys 42 are used, for example, forcommunication control.

In the operation control 4, the LCD 41 and the operation keys 42 arearranged in parallel in the X-axis section, and other operation keys 43and 44 are arranged in parallel in the Y-axis section. The operationkeys 43 designate ups and downs of volume and mute, while the operationkeys 44 are used to change the setup of the audio signaltransmission/reception device 1. The audio signal transmission/receptiondevice 1 has two setup modes, wherein, for example, it allows the userto select one of the first and second modes.

In the aforementioned operation control 4, the LCD 41 and the operationkeys 42, 43, and 44 are arranged in the Y-axis section (i.e., the frontside viewed from the user) so as to allow them to be easily recognized.This makes it possible for the user to easily operate and recognize theaudio signal transmission/reception device 1.

The LED display 5 linearly arranges two series of LEDs 51, wherein fiveLEDs are aligned in the -Y-axis section, and five LEDs are aligned inthe Y-axis section. In each series, multiple LEDs 51 are aligned in aradial manner extending from the -X-axis section to the X-axis section.The LEDs 51 are each independently controlled by a lighting controlsection (not shown) arranged inside of the upper panel 20. Specifically,when the user operates the operation keys 44 to set up the first mode,multiple LEDs 51 are appropriately turned on so as to designate thedirectivity of a sound beam emitted from the speaker array 231. That is,the user can visually recognize the directivity of a sound beam emittedfrom the speaker array 231 based on the lighting state of the LEDs 51.

When the user operates the operation keys 44 to set up the second mode,multiple LEDs 51 are appropriately turned on so as to designate thesound reception directivity of the microphone arrays 24. Since twoseries of microphone arrays 24 are installed in the main unit 2 of theaudio signal transmission/reception device 1, the LEDs 51 aligned in theY-axis section are turned on so as to designate the sound receptiondirectivity of the microphone array 24 of the Y-axis section, while theLEDs 51 aligned in the -Y-axis section are turned on so as to designatethe sound reception directivity of the microphone array 24 of the-Y-axis section. Thus, the user is capable of recognizing the manner ofsound reception by way of the LED display 5, whereby the user canrecognize the sound reception directivities regarding two series ofmicrophone arrays 24 by observing lighting states of two series of LEDs51.

The audio signal transmission/reception device 1 of the presentembodiment controls the sound reception directivity with respect toplural regions surrounding it, wherein it has a function to detect theposition of talker based on sound reception levels of regions. Thus, theuser can recognize whether the position of a talker is erroneouslydetected in the second mode.

The LEDs 51 are controlled to vary in lighting manners thereof inresponse to volumes of received sound and emitted sound in the LEDdisplay 5. This makes it possible for the user to recognize whethersound reception and sound emission are achieved with an adequate volume.

As shown in FIG. 3(A), the connectors 6 for establishing connection withan external device (not shown) are arranged in the side panel 22A of theX-axis section. As the connectors 6, there are provided a modular jack61 connected with a LAN such as the Ethernet (registered trademark) or anetwork such as the Internet; an audio input terminal 62A and an audiooutput terminal 62B connected with an audio device; and a power terminal63 connected with a power source.

Inserting the plug of a modular cable (not shown) into the modular jackmakes it possible to connect the audio signal transmission/receptiondevice 1 to a network. When the audio signal transmission/receptiondevice 1 is connected to the network, it can be communicated with acounterpart audio signal transmission/reception device, thus making itpossible to perform conversation and audio conference. Thus, it ispossible to use the audio signal transmission/reception device 1 as anIP telephone device and an audio conference device.

In the present embodiment, connectors are arranged in the side panel 22Ain a concentrated manner. This makes it possible to compactly design theaudio signal transmission/reception device 1 of the present embodimentin comparison with the foregoing audio signal transmission/receptiondevice in which connectors are arranged on the upper surface.

FIG. 4 is a bottom view of the audio signal transmission/receptiondevice 1 excluding the lower grill 21, and FIG. 5 is an enlargedperspective view of the audio signal transmission/reception device 1.FIG. 6 is a cross-sectional view of the audio signaltransmission/reception device 1 shown in FIG. 4 taken along line A-A.

The speaker array 231 and the microphone arrays 24 are attached to theframe 25 serving as a baffle of the speaker array 231. The frame 25 is abox-like member, which is formed by bending four corners of arectangular metal plate upwards. The speaker array 231 is attachedinside of the bottom of the frame 25 to direct downwardly, while themicrophone arrays 24 are arranged on both sides of the frame.

The lower end of an elongated cylindrical frame member 232 covering thesides of the speaker array 231 is arranged in the upper section of theframe 25. A top board 233 having substantially the same dimensions asthe bottom of the frame 25 is arranged in the upper end of the framemember 232 so as to cover the rear of the speaker array 231.

Support plates 26 each composed of a metal plate upwardly extended areattached to the sides of the frame 25 (i.e., bent portions lying in thelongitudinal direction) via screws 27A, wherein the upper ends of thesupport plates 26 are bent inward. The bent portions of the supportplates 26 are attached to terminal portions of the top board 233 in itswidth direction via screws 27B. That is, the frame member 232 is heldbetween the top board 233 and the bottom of the frame 25.

As described above, a housing 23A of the speaker array 231 is formed andsurrounded by the frame 25, the top board 233, and the cylindrical framemember 232. A printed circuit board (not shown) mounting a control unit(not shown) for performing directivity control on the speaker array 231and the microphone arrays 24 is attached to the surface of the housing23A (i.e., the surface of the top board 233). The speaker device 23 isconstituted by the control unit, the housing 23A, and the speaker array231.

A plurality of speaker units SP (e.g., sixteen speakers SP) are linearlyand uniformly aligned in the speaker array 231. A plurality of holes 251are formed in the bottom of the frame 25 in conformity with alignmentpositions of the speaker units SP. Each hole has the same dimensions asthe internal diameter of each speaker unit SP. In this condition, thespeaker array 231 is attached to the bottom of the frame 25 via screws252. That is, the sound emission side of the speaker array 231 isarranged in the bottom of the frame 25, from which sounds of the speakerunits SP are emitted.

In the present embodiment, the speaker array 231 is arranged on thebottom of the audio signal transmission/reception device 1, and theoperation control 4 and the LED display 5 are arranged in prescribedregions achieving good operability in view of the user (i.e., the uppersurface of the audio signal transmission/reception device 1). That is,the audio signal transmission/reception device 1 is compactly designedsuch that the operation control 4, the LED display 5, and the speakerarray 231 are compactly arranged in a three-dimensional manner. A soundbeam emitted from the speaker array 231 is emitted downwardly from theaudio signal transmission/reception device 1, wherein the audio signaltransmission/reception device 1 is supported at a prescribed heightabove the mount surface (e.g., the surface of a desk) by means of thelegs 3, so that the sound beam is reflected off the mount surface so asto slantingly propagate upwards. Thus, it is possible to transmit asound beam toward the user with an efficiency similar to that realizedby the audio signal transmission/reception device 1 arranging thespeaker array 231 on the lower surface thereof.

Since the legs 3 have hollow structures, it is possible to transmitsound toward the user without disturbing sound emission of the speakerarray 231 and reflection on the mount surface.

The control unit delays audio signals, which are inputted thereto viathe modular jack 61 from the counterpart audio signaltransmission/reception device so as to control the directivity of asound beam emitted from the speaker array 231. Audio signals from thecounterpart audio signal transmission/reception device are subjected toD/A conversion and amplification and are then supplied to the speakerarray 231.

The microphone arrays 24 includes two series of microphones 241 (eachseries includes sixteen microphones 241, for example), which arelinearly aligned on both sides of the frame 25 along its longitudinaldirection. A plurality of microphones 241 can be aligned in anon-uniform manner such that the density thereof increases in the insideof the frame 25; this makes it possible to efficiently receivehigh-frequency sound having high directivity.

The microphone arrays 24 are supported on both sides of the frame 25 bymeans of the support plates 26 forming cutouts 261 at positions of themicrophones 241, wherein the support plates 26 are fixed to both sidesof the frame 25 via screws such that the microphones 241 are put intothe cutouts 261.

In the present embodiment, two series of microphone arrays 24 arearranged on both sides of the speaker device 23, i.e. on both sides ofthe audio signal transmission/reception device 1. Thus, the operationcontrol 4 and the LED display 5 can be arranged only on the uppersurface of the audio signal transmission/reception device 1. Thus, it ispossible to compactly design the audio signal transmission/receptiondevice 1 in a three-dimensional manner. In other words, it is possibleto reduce the size of the audio signal transmission/reception device 1of the present embodiment compared with the foregoing constitution inwhich the speaker array and microphone array are arranged on the uppersurface of the audio signal transmission/reception device. In addition,the connectors 6 are arranged on the side surface, which differs fromthe side portions for arranging the microphone arrays 24, in the audiosignal transmission/reception device 1, which can be thus reduced insize.

The microphone arrays 24 are connected to the control unit via signallines (not shown); hence, audio signals converted by the microphones 241are supplied to the control unit. In the control unit, audio signals areappropriately delayed, thus performing directivity control on soundbeams. Then, audio signals are transmitted to the counterpart audiosignal transmission/reception device via the module jack 61 and modularcable (not shown).

According to the present embodiment described above, the speaker array231 is arranged on the lower surface of the audio signaltransmission/reception device 1; this allows the operation control 4 andthe LED display 5 to be arranged on the upper surface, which providesgood operability and good visual recognizability for the user; hence, itis possible to compactly design the audio signal transmission/receptiondevice 1. Since the audio signal transmission/reception device 1 issupported by the legs 3 at a prescribed height from the surface, it ispossible to determine the directivity in which a sound beam emitted fromthe speaker array 231 is reflected on the surface so as to slantinglypropagate upwards. Thus, as similar to the foregoing constitution inwhich the speaker array is arranged on the surface of the audio signaltransmission/reception device, it is possible for the audio signaltransmission/reception device 1 of the present embodiment to emit asound beam directed to the user.

The present embodiment provides the compact audio signaltransmission/reception device 1 that secures good user operability andthat can efficiently emit sound to the user.

Furthermore, two series of microphone arrays 24 are aligned on bothsides of the audio signal transmission/reception device 1in itslongitudinal direction, and the connectors 6 are collectively arrangedin one terminal surface of the audio signal transmission/receptiondevice 1. This allows the operation control 4 and the LED display 5 tobe arranged on only the upper surface of the audio signaltransmission/reception device 1; thus, it is possible to design theaudio signal transmission/reception device 1 in a further compactmanner. Since the microphone arrays 24 and the connectors 6 areindependently arranged in different sides of the audio signaltransmission/reception device 1, it is possible to further reduce thesize of the audio signal transmission/reception device 1.

Since the speaker array 231 is arranged on the lower surface of theaudio signal transmission/reception device 1 and the microphone arrays24 are arranged on both sides of the audio signal transmission/receptiondevice 1, it is possible to effectively prevent dust from entering intothe inside of the audio signal transmission/reception device 1 via holesof a punch mesh member, and it is possible to effectively prevent dustfrom being attached to the lower surface of the speaker device 23 or thesupport plates 26.

INDUSTRIAL APPLICABILITY

The present invention is applicable to the audio signaltransmission/reception system realizing audio conferences in theenterprise or between distanced places.

This application is a U.S. National Phase Application of PCTInternational Application PCT/JP2006/321249 filed on Oct. 25, 2006 whichis based on and claims priority from JP 2005-312964 filed on Oct. 27,2005, the contents of which is incorporated herein in its entirety.

The invention claimed is:
 1. An audio conference device comprising: amain body having a prescribed shape and having a lower surface, an uppersurface, opposing first and second side surfaces, and a third sidesurface extending between the opposing first and second side surfaces; aspeaker array having a plurality of speakers arranged on the lowersurface of the main body; an operation control arranged on the uppersurface of the main body; a microphone array having a plurality ofmicrophones arranged on at least one of the first or second side surfaceof the main body, with each of the plurality of microphones positionedhigher than the lower surface to minimize the microphones fromcollecting sound output from the speaker array; at least one legextending below the lower surface of the main body so that the speakerarray is positioned at a prescribed height above a surface on which theaudio conference device rests; and at least one connector, through whicha connection is established with another audio conference device,arranged on the third side surface of the main body near a leg among theat least one leg.
 2. The audio conference device according to claim 1,wherein: the main body has an elongated rectangular parallelepipedshape, the opposing first and second side surfaces of the main bodyextend along a longitudinal direction thereof, and the third sidesurface of the main body extend along a width direction thereof.
 3. Theaudio conference device according to claim 1, wherein a pair of legs,each having an open structure to permit sound waves to pass therethroughto minimize interference with sound output from the speaker array, areprovided at opposing ends.
 4. The audio conference device according toclaim 1, further comprising a display that displays sound emissioncharacteristics of the speaker array.
 5. The audio conference deviceaccording to claim 1, further comprising a display that displays thesound reception characteristics of the microphone array.
 6. The audioconference device according to claim 3, were each of the legs isU-shaped.